Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

OSPF route summarization

I have multiple interfaces in /22 maks (10.x.x.x/22) and I also have an interface with /16 mask (10.0.0.0/16) on the same router. I'm trying to summerize these addresses into OSPF area. Both of these interfaces are in area 0, can someone suggest me a better way to do the summarization or should I put these interfaces into different area?

Thanks.

1 REPLY

Re: OSPF route summarization

Hello,

OSPF will always advertise all networks internal to an area to all routers in the area through LSA1 (router LSA).

The only way to summarize internal routes is on an ABR with "area 10 range 10.0.0.0 255.255.0.0".

So place all interfaces in a different area 10 (use an area number not yet present) and utilize the area range command above. The ABR will then announce the summary route with an LSA3.

For a detailed explanation of the command have a look at

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_reference_chapter09186a00800917e6.html#wp1017596

Hope this helps! Please rate all posts.

Regards, Martin

99
Views
0
Helpful
1
Replies
CreatePlease login to create content